You have just described the first step in the chain towards getting your info stolen.All that said, the exact same stuff can happen to an Android phone. Personally, I feel a lot more secure dealing with an Apple employee in an Apple store than I ever will dealing with some guy at a mall cellphone repair shop...which is the only viable option for a owners of other brands of cellphones who simply don't have the benefit of a direct manufacturer chain of service facilities.
Trust no one. Regardless of the device, if it needs to be handled by another party you must either: look over their shoulders as they work on the phone to make sure they don't explore any content they have no business exploring, or; wipe the phone after having performed a backup (the Apple store won't and shouldn't help you with that BTW).